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Case split, what needs replacing?
- Bdee
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Case split, what needs replacing? was created by Bdee
I split the case of my ct3 because I found some small metal pieces in the transmission oil that were attracted to a magnet. I haven't found any damage yet; I intend to dismantle the transmission to take a closer look.
While the the case is split, I was wondering besides the crank bearings and seals what else should I replace? I did try searching for the answer but I didn't find any hits that addressed anything but crank bearings or damaged parts.
thanks,
Rob
While the the case is split, I was wondering besides the crank bearings and seals what else should I replace? I did try searching for the answer but I didn't find any hits that addressed anything but crank bearings or damaged parts.
thanks,
Rob
15 Dec 2023 10:00
#1
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- RT325
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Replied by RT325 on topic Case split, what needs replacing?
Where do you stop, how is the bigend.
If ya confident at dismantling after doing it once & can do it again easily at a far later date & if the bigend feels ok then just do seals.
If in doubt then do mains too.
Big thing at the moment is gearbox shrapnel & finding the cause. [in my opinion, & i hate spending money lol].
If ya confident at dismantling after doing it once & can do it again easily at a far later date & if the bigend feels ok then just do seals.
If in doubt then do mains too.
Big thing at the moment is gearbox shrapnel & finding the cause. [in my opinion, & i hate spending money lol].
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- RT360Fan
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Replied by RT360Fan on topic Case split, what needs replacing?
Since you're in there . . . Inspect the connecting rod crank clearance. If out of spec good time for a crank rebuild.
15 Dec 2023 15:00
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- Bdee
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Replied by Bdee on topic Case split, what needs replacing?
There is no vertical play in the connecting rod. I will check the horizontal as soon as I look up the tolerances.
The splitting went smoothly. I anticipate having much more difficulty in the re-assembling.
Thanks for the feedback.
The splitting went smoothly. I anticipate having much more difficulty in the re-assembling.
Thanks for the feedback.
16 Dec 2023 12:24
#4
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- LongStride
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Replied by LongStride on topic Case split, what needs replacing?
Check the transmission bearings close, that may be the source of the shavings, the output shaft bearing next to the drive chain takes a lot of strain, seen bearing failure on the one the clutch sits on
2ET703 Central Texas
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16 Dec 2023 17:05
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- RT325
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Replied by RT325 on topic Case split, what needs replacing?
Revolve the crank to see if you can feel any roughness because the rod looses hardening most likely at the top of the bigend eye circle.
The rollers often just loose hardening over part of their diameter.
So when they roll to the point of the missing hardening on rollers & rod aligning it'll go rough at that point then smooth out until the next lap.
That's maybe exaggerating things a bit.
I got caught out once doing mains that were growling but it was also the bigend.
Hope yours is ok.
The rollers often just loose hardening over part of their diameter.
So when they roll to the point of the missing hardening on rollers & rod aligning it'll go rough at that point then smooth out until the next lap.
That's maybe exaggerating things a bit.
I got caught out once doing mains that were growling but it was also the bigend.
Hope yours is ok.
16 Dec 2023 17:51
#6
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- MarkT
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Replied by MarkT on topic Case split, what needs replacing?
Really hard to feel vertical rod movement. I had a rod once that felt perfect, no growling, no discernible vertical play.... made the big end clicking noise when it was back together and running.
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Pulled the cylinder and tested the small end rod "wobble" as described in the manual. Was out of spec. Rebuilt crank and nice and quiet.
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Pulled the cylinder and tested the small end rod "wobble" as described in the manual. Was out of spec. Rebuilt crank and nice and quiet.
1963 YG1-T, 1965 MG1-T, Allstate 250, 1970 CT1b, 1971 R5, 1973 AT3MX, 1974 TS400L, 1975 RD350, 1976 DT175C, 1976 Husqvarna 250CR, 1981 DT175G, 1988 DT50, 1990 "Super" DT50, 1991 RT180, 2017 XT250
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- Bdee
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Replied by Bdee on topic Case split, what needs replacing?
Thanks for the additional info. Can't have too much. or at least I can't
I tested for horizontal play at the small end; it was less then 2mm and only a .43mm feeler could fit inside the gap between the rod and the lobe. I really don't know what the two heavy discs on a crankshaft are called, lobe sounds good.
I need to purchase a dial gauge holder to test the crank run-out. But I have plenty of time until march
How does one test a needle bearing?
I tested for horizontal play at the small end; it was less then 2mm and only a .43mm feeler could fit inside the gap between the rod and the lobe. I really don't know what the two heavy discs on a crankshaft are called, lobe sounds good.
I need to purchase a dial gauge holder to test the crank run-out. But I have plenty of time until march
How does one test a needle bearing?
16 Dec 2023 18:41
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- shyted
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Replied by shyted on topic Case split, what needs replacing?
I see it like this,replace all the bearings and seals. Do that then you know it's all new.Replace the lock washers and dont forget the O ring on the crank primary side. I'm quite sure you will have two crank shims, one each side, within the case too so don't lose them. Information is power ! So if you don't have one,download the free manual from here, it's on the Tech Page section of the task bar at the top.
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23 Dec 2023 04:58
#9
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